1. Field of the Invention
The present invention relates to a deodorant sheet which has both a deodorant effect and antibiotic activities such as antibacterial, antimold and vermin-proof activities that are fast to washing, and which can, therefore, be used for multiple purposes in the daily environment.
2. Description of the Prior Art
Deodorants are classified into adsorptive type ones and reactive type ones according to the mechanism thereof. A divalent iron compound which is a reactive type deodorant, particularly ferrous sulfate, has a strong deodorant effect for malodorous components originating from ammonia, amine, and the like. Thus, it is used as a deodorant by being carried on a carrier such as an activated carbon or zeolite. Further, it is incorporated into various daily necessaries such as calendars, posters, and wallpaper. Thus, daily necessaries having a deodorant effect, for example, a deodorant calendar, may be marketed.
The deodorant activity of ferrous sulfate is so strong that it is quickly reacted with ammonia even when it is carried on a cloth by impregnating the cloth therewith. However, it is oxidized with oxygen in the air to develop a yellowish brown color and it has a tendency to decrease its deodorant capacity. Therefore, the application of its deodorant capacity to a material having a long service period has been difficult. An increase in an amount of ferrous sulfate for the purpose of enhancing the deodorant effect of such a material leads to a serious influence of coloring.
Since ferrous sulfate is soluble in water, ferrous sulfate carried on a cloth is readily removed when washed with water, resulting in the loss of the desired deodorant effect. And what is worse, the yellowish brown color itself which is formed cannot be readily removed. Accordingly, the application of ferrous sulfate to clothing and bedding has been difficult.
Further it is found that, where a sheet material is a porous material compatible with a film-forming substance, incorporation of a ferrous sulfate monohydrate powder into the film forming substance can advantageously provide a deodorant sheet material free of any change in appearance with time. Moreover, the sheet has a persistent deodorant capacity and a fastness to washing with water or cleaning when the chain film-forming substance is resistant to water. This is disclosed in Japanese patent publication A No. 62-64538, which is after the priority date of the application.